Dyeable acrylonitrile copolymers



Patented Oct. 20, 1953 2,656,326 DYEABLE scnrtomranic COPOLYMERS George E. Ham, Dayton, Ohio, assignor, by mesne assignments, to The Chemstrand Corporation, a corporation of Delaware No Drawing.

Application March 23, 1950,

Serial No. 151,523

This invention relates to new dyeable fiberforming compositions. More specifically, the invention relates to copolymers of acrylonitrile capable of being spun into dyeable textile fibers.

In copending application Serial No. 123,093, filed October 22, 1949, by George E. Ham, of which the present application is a continuation-in-part, there are described and claimed new fiber-forming copoylmers of acrylonitrile and methallyl esters of halogen-substituted aliphatic monocarboxylic acids. The application also describes various methods of converting the non-dyeable copolymers into dyeable copolymers by treatment with ammonia and various amines, which aftertreatment may be conducted on the solid copolymers, solution of the copolymer or on the fibers fabricated from the copolymers. The aftertreatment of the solid copolymer or the fiber are often not effective in inducing sufficient dye affinity for conventional general purpose usage, unless a high proportion of haloacetate groups are present, in which case the incident depreciation in fiber properties makes operations less practicable. The said application also describes reaction of the copolymer with the amines in solution in a suitable solvent, for example N,N-dimethylacetamide, gamma-butyrolactone, and mixtures of water and nitromethane, but this procedure is often impracticable or difficult because of the gelation of the solution, which takes place if the solutions; are not spun soon after their preparation.

12 Claims. (Cl. 26029.1)

Similarly, in the case of temporary shutdowns in the fiber-spinning process unstable polymer solutlons may result in serious loss of time and equipment.

The primary purpose of this invention is to provide a method of preparing fibers of improved dye receptivity. A further purpose is to provide a method of spinning involving solutions of polymers not susceptible to gelation. A still further purpose of this invention is to provide a method of converting non-dyeable copolymers ofacrylonitrile and methallyl chloroacetate into dyeable copolymers by a convenient practicable procedure.

In accordance with this invention it has been found that when copolymers of methallyl halo acetates and acrylonitrile are treated with either trimethylamine or triethylamine in a solution, the copolymer is rendered dyeable by conversion of the chloroacetate groups into quaternary ammonium radicals without experiencing the usual increase in viscosity or gelation. This reaction 5 appears to be specific with trimethyland triethylamine, since almost invariably the use of is treated in dimethylacetamide or other solvent,

solution with trimethylamine, almost immediate g'elation occurs. The treatment of copolymers of acrylonitrile and methallyl chloroacetate in accordance with this invention induces dyeability without any sign of gelation. In fact the treatment may in some cases make the methallyl chloroacetate copolymer solutions more stable than copolymer solutions untreated with the trimethylor triethylamine.

This invention is practicable with fiber-spinning copolymers of '75 to 99.5 percent acrylonitrile and from 0.5 to 25 percent of methallyl haloacetate. Since the copolymers of more than 98 percent acrylonitrile and less than two percent of the methallyl esters do not contain suflicient reactive groups to produce copolymers of optimum dye receptivity, and since copolymers having less than percent acrylonitrile often do not posses the optimum fiber properties, the preferred class of copolymers are those of 85 to 98 percent acrylonitrile and from two to 15 percent of the methallyl esters of haloacetic acids.

The copolymers used in the practice of this invention may be prepared by any polymerization procedure but preferred practice utilizes a suspension polymerization in which the reactant monomers are heated in the presence or a suitable free radical catalyst in an aqueous medium.

Usually the reaction requires a dispersant to prevent the agglomeration of the copolymer during its formative stage. The polymerization reaction may be a batch procedure or it may be continuous. Avery desirable procedure is the semi-continuous type in which the monomers are gradually added to an aqueous medium in a reactor and the polymer produced is recovered after a pre-determined quantity of monomers has been reacted. Conventional procedures with respect to the use of regulators, continuous or intermittent addition of catalyst and dispersing agent.

low-temperature redox methods and other known procedures for producing uniform copolymers of desired molecular weights are also feasible.

The copolymers preferred in the practice of this :5

invention are those of uniform physical and chemical properties and preferably of higher molecular. weight.- .The copolymers. will have;

other amines induces an increased viscosity or- 3 molecular weights in excess of 10,000 and preferably between 25,000 and 150,000.

The copolymers are rendered dyeable by reaction with either trimethylamine or triethylamine while dissolved in a suitable solvent. Suitable solvents for the conduct of the reaction may be any "of (the i conventional acrylonitrile solvents, sor'ne-cf which are well known to the art and widely described in published literature. Examples of suitable solvents are: N,N-dimethylacetamide, N,N-dimethylformamide, tris(N,N-

dimethylamino) -phosphine oxidefblityrolactcriey a-cyanoacetamid'e,= N;N-dimethylmethoxyacetamide, a emiirture of water maleic anhydride,

and nitromethane, and other substances known to dissolve high acrylonitrile copolymers.

v with respect to the following examples.

The reaction is conducted by dissblviii'g or'dis-' persing finely divided polymers in sufficient solvent to produce a solution of from ten to 25 mm:

cent of the copolymer. The liquid triethylamine or; the *gaseous trimethylamine, may be mixed directly Lwith'the polymer-solution, -orpreferably,-

may :be' dissolved ina 1 small proportion of the same orw'other acrylonitrile solvent and the two liquids blended by conventional mixing proce duress A convenient 1 method; of cond-uctingthe reaction-involves the dispersion of the finely dividedcopolymer-at a temperature below that atwhich solutionsare readilyformed and thereafter adding-and mixingtherewith the triethylor-trimethylamine,- or asolution of the said trialkylarnine before a'viscous polymer solution has beerrprepared; After athorough mixing of the reage.nts-,--v the reaction r-mi-xture -may then be heated to a temperature at which the viscous copolymer solution :isreadily-formed, The higher final temperature also serves tocomplete the quaternization reaction between the chloroacetate groups :and z the tr-ialk-ylamin-e's; and thereby develomthe-optimum-dyeing--.properties.-

The quaternizationreaction between i the methal lyl: ichloroacetate and '7 tr-imethylamine is believed" to involve the reactionrepresented by the equation: 1

wherein a: is a numberirfdicativeof the degree of pOly merization.

The "solutions of the copolymers which havebeen quaternized by reaction'of the trimethyl receptive and stableto gelation over longperiods withffthi's inventionm'ay in some instances be mbr stametd gelatioii than i solutions j or th'e samej' zcop'olymer which have not" been 7 treated with "tr'iethyl or trimethylamin'ep" The; stable solutionsfof "dyeable-copolymer's may be spun intofuseful' and-valuablefibers by conventional spinning procedures. The"'solu-" tions mayfbe extruded through dies and spin-' eretsbontainingia plurality of -apertiires -into a medium'which extracts thezsoiventaanu' precipie tates: tliisoli'd' poiym in a 'bontihu'ous fibrous foi'm. Biith'fthe "dry-spinning: method;in'='which the Said medi'um'is Ea gasjdand :the wet spinning -1- Example 1 A- copolymer of llfi-fi percent acrylonitrile and 4.5 -perh'er'it of 'methally1 chloroacetate was preparedbyuaddingwthe premixed monomers to an a q us meuiu'mpver a two hour period at C. The reaction was catalyzed with 0.3 percent of potassium persulfate based on the weight of the monomers and was conducted in the presence of 0.6 percent of tertiary dodecyl mercaptan as a regulator. The dispersion of-the reactants was maintained by the useof0.1 percent of sodiumsalt of -mi-xed"mahogany acids. After all the monomers had been added the reaction was continued forone-half hour at'thereflux temperature,- and --thensteam distilled to remove unreacted monomers.-- Theresulting copolymer was found to have 'a specific-viscosity of 0.20 in 0.1 percent solutions of the copolymer in N,N-

'35 pensi0n of solid polymerin thesolvent. The

suspension was-then m-ixed witha solution of 18 grams of trimethylamine in 196 grams of N,N-dimethylacetamide at 30 0. forten minutes, atwhich time- "the entire mixture was" =heated to- Crandmaintained there until the resin -wascompletely dissolved. The treated solution was stored for one hundred hours with no :visible signs of-gelation or measurable increase in viscosity The treated solutions were spun into fibers by extruding-through a spinnerethaving 30ap'er-' tures, each 0.005 inch in diameter; into a mixture of 60- -percent by weight of dimethylacetamide and 40 percent waterl The fiber so produced was stretched 200 percent and dyed with-stand ard-dyeing procedure;- The fibers wer'e effectively dyed-with- Wool-Fast Scarlet,-Alizarin-' 1Light Blue,- Acid' Green 00 and Wool'Fast Yel Ezzl'ample 2 A solution 'ofthecopolymer-described in Example "1 "was prepared using N,N=dimethylacetamide," by mixing' the polymer and*'solvent at 30 C. The suspensionwa'sthen converted into a solutioriby increasing the temperature to 85- C.} The'solution 2 was then cool'e'd to '30 -'C; and" t a separately "prepared solution of 8.5 percenttrimethylainine in N,N dimethy1'acetamide" was added thereto approximately stoichiometric proportions. The treated solution was' 'then' heated to=50 Cain which condition it'wasstored for over one hundredhoursa' No'gelation and no" measurableincrease in viscosity occurred after the trimethylamine was" added: E

Example 3 Theprocedure of Examp1'e 1 was repeated,

using= =allylchloroacetatein place of methally-li chl'oroacetate; The-solution became gelled withi rt 75 11 time after the trimethylamine wa' added and the gelation took place more rapidly than a similar solution which had not been treated with trimethylamine.

Example 4 A copolymer of 93.3 percent by weight of acrylonitrile and 6.7 percent of methallyl chloroacetate was prepared as in Example 1. The specific viscosity in 0.1 percent of N,N-dimethylformamide was found to be 0.16.

The polymer was dissolved in N,N-dimethylacetamide to produce a 19 percent solution. A stoichiometric quantity of a ten percent solution of trimethylamine in N,N-dimethylacetamide was mixed therewith. The mixture was heated at 45 C. for 35 minute without gelation or increase in viscosity. The polymer solution was then spun into fibers by extrusion through a thirty-hole spinneret into a mixture of 60 percent dimethylacetamide and 40 percent water. The fibers were then stretched 200 percent and dyed with a Wool Fast Scarlet dye bath containing 0.02 grams of dye and 5.0 grams of three percent sulfuric acid for each gram of fiber. The dye bath was exhausted in one hour at 100 C. The dyed fiber was fast to laundering and dry cleaning.

The invention is defined by the following claims:

1. A method of preparing dyeable acrylonitrile copolymers, which comprises heating a copolymer of 75 to 99.5 percent of acrylonitrile and 0.5 to 25 percent of methallyl haloacetate, with a compound selected from the group consisting of triethylamine and trimethylamine.

2. A method of preparing dyeable acrylonitrile copolymers, which comprises heating in solution a copolymer of 80 to 98 percent of acrylonitrile and two to 20 percent of methallyl haloacetate, with a compound selected from the group consisting of triethylamine and trimethylamine.

3. The method described in claim 1, wherein the halogen is selected from the group consisting of chlorine and bromine.

4. The method described in claim 2, wherein the halogen is selected from the group consisting of chlorine and bromine.

5. The method of preparing a dyeable copolymer, which comprises heating a copolymer of 80 to 98 percent of acrylonitrile and two to 20 percent of methallyl chloroacetate with trimethylamine.

6. The method of preparing a dyeable copolymer, which comprises heating a copolymer of 80 to 98 percent of acrylonitrile and two to 20 percent of methallyl chloroacetate with triethylamine.

'7. A method of preparing dyeable acrylonitrile copolymers, which comprises mixing a copolymer of to 99.5% of acrylonitrile and 0.5 to 25% of methallyl haloacetate in a solvent therefor, and quaternizing the copolymer by adding a compound selected from the group consisting of trimethylamine and triethylamine and heating the mixture.

8. The method described in claim 7 wherein the halogen is selected from the group consisting of chlorine and bromine.

9. A method of preparing dyeable acrylonitrile copolymers, Which comprise mixing a copolymer of to 98% of acrylonitrile and two to 20% of methallyl haloacetate in a solvent therefor, heating the mixture to dissolve the copolymer. and quaternizing the copolymer by adding to the solution a compound selected from the group consisting of trimethylamine and triethylamine while heating the solution.

10. The method described in claim 9, wherein the halogen is selected from the group consisting of chlorine and bromine.

11. The method described in claim 9 wherein the haloacetate is methallyl chloroacetate and the quaternizing compound is trimethylamine.

12. The method described in claim 9 wherein the haloacetate is methallyl chloroacetate and the quaternizing compound is triethylamine.

GEORGE E. HAM.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Nov. 5, 1945 

1. A METHOD OF PREPARING DYEABLE ACRYLONITRILE COPOLYMERS, WHICH COMPRISES HEATING A COPOLYMER OF 75 TO 99.5 PERCENT OF ACRYLONITRILE AND 0.5 TO 25 PERCENT OF METHALLYL HALOACETATE, WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF TRIETHYLAMINE AND TRIMETHYLAMINE. 